Hanger insert for prestressed concrete



H LIA & WW ,1. 1... WATTS HANGER INSERT FOR PRESTRESSED CONCRETE FiledOct. 9, 1965 INVENTOR t HN WA 775 ATTORNEY United States Patent3,289,379 HANGER INSERT FOR PRESTRESSED CONCRETE John L. Watts, RD. 1,Box 1905, Port Orange, Fla. Filed Oct. 9, 1963, Ser. No. 314,937 Claims.(Cl. 52-689) This invention relates to a novel insert or anchor which isprimarily adapted to be embedded in a prestressed concrete member, suchas an overhead 'beam, and which is utilized for suspending a supportingbracket which may be employed for supporting various items such aselectric conduits or electric fixtures.

More particularly, it is an object of the present invention to provide aconcrete insert or embedded anchor which may be formed entirely ofplastic and which will facilitate the attachment thereto of a fasteningof the supporting bracket.

Still a further object of the invention is to provide an insert whichmay be readily located in a concrete beam or the like for the attachmentof the supporting bracket thereto.

Still a further object of the invention is to provide an insert whichmay be adjusted as to length to accommodate it to prestressed concretemembers the bottom wire ropes of which are spaced different distancesfrom bottom surfaces of the concrete members.

Various other objects and advantages of the invention will hereinafterbecome more fully apparent from the following description of thedrawing, illustrating presently preferred embodiments thereof, andwherein:

FIGURE 1 is a side elevational view of the insert in an applied positionrelative to a portion of a concrete beam and a portion of a mold forsaid beam;

FIGURE 2 is a vertical sectional view, partly in elevation, of theinsert and showing a part of the concrete beam in cross section in whichsaid insert is embedded;

FIGURE 3 is an elevational view of the insert, looking from left toright of FIGURE 2;

FIGURE 4 is a bottom plan view of a part of the concrete beam in whichthe insert is embedded, and

FIGURE 5 is a fragmentary side elevational view, partly in verticalsection, illustrating a modification of the insert.

Referring more specifically to the drawing, and first with reference toFIGURES 1 to 4, the insert in its entirety and comprising the inventionis designated generally 6 and includes a lower section, designatedgenerally 7, and an upper section, designated generally 8. The lowersection 7 includes an upright stem 9 which is preferably of circularcross section and which includes a lower portion 10 and an upper portion11. The lower portion 10 is of a diameter somewhat greater than that ofthe upper portion 11. The lower portion 10 is provided with a plurality,preferably four, arms 12 which extend radially therefrom and which areequally spaced relative to one another. The arms 12 are spaced from theends of said lower portion 10 and are disposed coplanar with oneanother. A foot member 13 extends downwardly from each arm 12, near itsouter end. The lower ends of the corresponding foot members 13 aredisposed coplanar with one another and with the fiat lower end 14 of thelower stem portion It The stem 9 is provided with a blind bore 15 whichextends upwardly from said lower end 14 thereof and which is taperedtoward its upper end. The tapered bore 15 preferably extends through thelower stern portion 10 and slightly into the upper stem portion 11. Allof the aforedescribed parts of the lower section 7 constitute aone-piece molded plastic unit.

The upper section or head 8 likewise constitutes a onepiece moldedplastic unit and includes a U-shaped top portion or yoke 16 from thebase of which depends a 'ice downwardly opening socket or cap 17. Thecap or socket 17 is of a correct internal size to snugly receive theupper portion of the upper stem part 11.

Assuming that the sections 7 and 8 are assembled together, asillustrated in FIGURES 1 to 3, to form the insert or anchor 6, saidinsert 6 is positioned in a bottom portion 18 of a conventional mold andwith the foot members 13 and the base end 14 resting flush on the uppersurface 19 of the mold bottom, and with the yoke 16 engaging under aportion of a lowermost tensioned wire rope 20, so that said wire ropeportion seats in the yoke 16 for wedging the insert 6 between said wirerope portion and the surface 19. Concrete 21 is then poured into themold portion 18 and is subjected to vibration during pouring, as isconventional. The inner surface of the steel mold portion 18 is highlypolished and smoothed. Accordingly, it is essential that the insert 6 bewedged tightly between the wire rope 20 and the surface 19 in order tomaintain the base end 14 and the terminals of the foot members 13 fiushagainst said surface 19 during pouring, vibration and setting of theconcrete 21, so that thereafter when the form 18 is removed saidterminals of the foot members and the stem base 14 will be exposed andflush with the bottom surface 22 of the prestressed concrete beam 21.

The prestressed concrete beam usually includes several vertically spacedtensioned wire ropes, corresponding to the wire rope 20. Since theinsert 6 functions only in conjunction with the bottommost wire rope,the remain ing wire ropes have not been illustrated. The upper section 8is constructed separable from the lower section 7 because the bottomtensioned wire rope 20 may be spaced different distances from thesurface 19. Accordingly, the stem portion 11 may initially be madelonger than as shown and cut off to a proper length, as illustrated inFIGURES 1 and 2, before application of the upper section or head 8.

A tapered metal screw 23, which extends upwardly through a conventionalhanger bracket 24, is screwed into the bore 15 and in being appliedthereto will tap said bore. The bracket 24 may be utilized forsupporting such items as electrical fixtures or electrical conduits. Byutilizing a self-tapping screw 23 in the bore of the plastic stem 9, ifit is necessary to remove the fastening 23, it can always be replacedwith a slightly larger fastening for re-tapping the bore 15.

The exposed base 14 with its bore 15, surrounded by the exposedterminals of the foot members 131, will enable the bore 15 to be readilylocated for application of the fastening 23 thereto. The arms 12 assistin effectively anchoring the insert 6 in the concrete 21. The insert 6,although being made of plastic, becomes practically indestructible dueto being embedded in the concrete and as it is not exposed to sunlightit will not oxidize. The plastic is slow burning and an immense amountof heat is necessary to ignite it. The bracket 24 is capable ofsupporting a constant pull in excess of two hundred pounds without riskof the fastening 23 being pulled from the bore 15.

In some instances, the lowermost wire rope 20 is spaced a considerabledistance from the bottom surface 19 of the form 18. FIGURE 5 illustratesa modification of the insert which includes, in addition to the lowersection 7 and upper section 8, an intermediate section, designatedgenerally 25, and which includes an elongated stem 26 of the same crosssectional size and shape as the upper stem portion 11 and which isprovided at its lower end with a downwardly opening socket 27,corresponding to the socket 17. The socket 27 engages detachably overthe upper end of the stem 11, in the same manner as the socket 17, andthe upper end of the stem 26 fits into the socket 17, in the same manneras the stem portion 11. Like the stem portion 11, the upper end of thestem 26 may be cut off to vary the over-all length of the insert 28, asillustrated in FIGURE 5, to accommodate said insert to wire ropes spaceddifferent distances from the bottom surface 19 of the form.

Various other modifications and changes are contemplated and may beresorted to, Without departing from the function or scope of theinvention as hereinafter defined by the appended claims.

I claim as my invention:

1. An insert for a concrete structural member adapted to be wedgedbetween a part of a metal form and a lowermost tensioned wire ropedisposed parallel to said form part comprising, a lower section and anupper section, said lower section comprising an upright stem having asubstantially fiat bottom surface adapted to rest flush on an uppersurface of a part of a form, said stem having a longitudinal boreopening outwardly of said bottom surface, arms extending radially fromsaid stem and disposed above and spaced from said bottom surface and inspaced apart relation to one another, solid foot members depending fromouter portions of said arms and having lower ends disposed coplanar withone another and with said bottom surface and adapted to rest on saidupper surface of the form part; said upper section comprising adownwardly opening socket having a smooth bore engaging detachably overa smooth exterior of the upper end of said stem and an upwardly openingyoke, consisting of a base portion and upstanding spaced apart terminalelements, in which a tensioned wire rope is adapted to seat for Wedgingthe insert between the wire rope and said upper surface of the form partto be embedded in concrete applied to said form such that said bottomsurface of the stern and the lower ends of said foot members will beexposed when the form is removed from the set concrete, said bore beingadapted to receive and secure a hanger bracket fastening to the insertfor suspending a hanger bracket therebeneath and beneath the concretestructural member.

2. An insert as in claim 1, said lower section and said upper sectioneach constituting a one-piece plastic unit.

3. An insert as in claim 1, said upper section and said lower sectioneach constituting a one-piece plastic unit, said stem including a lowerportion and an upper portion, said arms being disposed intermediate ofthe ends of the lower portion, said upper portion being of smaller crosssectional size than the lower portion of uniform cross sectional sizethroughout its length and being adapted to be cut off for varying theoverall length of the stern and the overall height of the assembledinsert.

4Q An insert for a concrete structural member adapted to be wedgedbetweena part of a metal form and a lowermost tensioned wire ropedisposed parallel to said form part comprising, a lower section and anupper section, said lower section comprising an upright stem having asubstantially fiat bottom surface adapted to rest flush on an uppersurface of a part of a form, said stem having a longitudinal boreopening outwardly of said bottom surface, arms extending radially fromsaid stem and disposed above and spaced from said bottom surface and inspaced apart relation to one another, foot members depending from outerportions of said arms and having lower ends disposed coplanar with oneanother and with said bottom surface and adapted to rest on said uppersurface of the form part; said upper section comprising a downwardlyopening socket engaging detachably over the upper end of said stemand anupwardly opening yoke in which a tensioned wire rope is adapted to seatfor'wedging the insert between the wire rope and said upper surface ofthe form part to be embedded in concrete applied to said form such thatsaid bottom surface of the stem and the lower ends of said foot memberswill be exposed when the form is removed from the set concrete, saidbore being adapted to receive and secure a hanger bracket fastening tothe insert for suspending a hanger bracket therebeneath and beneath theconcrete structural member, said stem including a detachable upperportion defining an intermediate section of the insert having an upperend engaging detachably in said downwardly opening socket of the uppersection and a lower end provided with a down wardly opening socketreceiving a portion of the stern of said lower section. I

5. An insert as in claim 4, said lower section, upper section andintermediate section each constituting a onepiece plastic unit.

References Cited by the Examiner UNITED STATES PATENTS 1,088,290 2/1914McAllister et a1. 52-699 1,218,378 3/1917 Dippel 52-704 1,677,140 7/1928Ketterman 52-688 X 2,306,671 12/1942 Tamblyn 52-678 2,867,041 1/1959McMillan 52-704 X 3,099,108 7/1963 Kalkbrenner 52-701 X 3,209,50910/1965 OCallaghan 52-688 3,225,506 12/1965 Aberg 52-687 FOREIGN PATENTS233,066 1/1961 Australia.

RICHARD W. COOKE, 111., Primary Examiner. FRANK L. ABBOTT, Examiner. A.C. PERHAM, Assistant Examiner.

1. AN INSERT FOR A CONCRETE STRUCTURAL MEMBER ADAPTED TO BE WEDGEDBETWEEN A PART OF A METAL FORM AND A LOWERMOST TENSIONED WIRE ROPEDISPOSED PARALLEL TO SAID FORM PART COMPRISING, A LOWER SECTION AND ANUPPER SECTION, SAID LOWER SECTION COMPRISING AN UPRIGHT STEM HAVING ASUBSTANTIALY FLAT BOTTOM SURFACE ADAPTED TO REST FLUSH ON AN UPPERSURFACE OF A PART OF A FORM, SAID STEM HAVING A LONGITUDINAL BOREOPENING OUTWARDLY OF SAID BOTTOM SURFACE, ARMS EXTENDING RADIALLY FROMSAID STEM AND DISPOSED ABOVE AND SPACED FROM SAID BOTTOM SURFACE AND INSPACED APART RELATION TO ONE ANOTHER, SOLID FOOT MEMBERS DEPENDING FROMOUTER PORTIONS OF SAID ARMS AND HAVING LOWER ENDS DISPOSED COPLANAR WITHONE ANOTHER AND WITH SAID BOTTOM SURFACE AND ADAPTED TO REST ON SAIDUPPER SURFACE OF THE FORM PART; SAID UPPER SECTION COMPRISING ADOWNWARDLY OPENING SOCKET HAVING A SMOOTH BORE ENGAGING DETACHABLY OVERA SMOOTH EXTERIOR OF THE UPPER END OF SAID STEM AND AN UPWARDLY OPENINGYOKE, CONSISTING OF A BASE PORTION AND UPSTANDING SPACED APART TERMINALELEMENTS, IN WHICH A TENSIONED WIRE ROPE IS ADAPTED TO SEAT FOR WEDGINGTHE INSERT BETWEEN THE WIRE AND SAID UPPER SURFACE OF THE FORM PART TOBE EMBEDDED IN CONCRETE APPLIED TO SAID FORM SUCH THAT SAID BOTTOMSURFACE OF THE STEM AND THE LOWER ENDS OF SAID FOOT MEMBERS WILL BEEXPOSED WHEN THE FORM IS REMOVED FROM THE SET CONCRETE, SAID BORE BEINGADAPTED TO RECEIVE AND SECURE A HANGER BRACKET FASTENING TO THE INSERTFOR SUSPENDING A HANGER BRACKET THEREBENEATH SAID BENEATH THE CONCRETESTRUCTURAL MEMBER.